Many surveillance or monitoring systems of today generates a lot of monitoring data from all types of sensors. Moreover, these systems are becoming more and more digitized and it is increasingly common to include video cameras in these systems. In order to be able to review events of interest the surveillance or monitoring data is recorded. Now, when most of the data is digital, the recording of the data implies storing the data in storage units. However, video data requires a lot of storage capacity for recording and a lot of bandwidth for transport of the data.
In order to solve the problem of the high demand of storage capacity the surveillance sensors and in particular the video cameras have been made more and more intelligent to avoid sending monitoring data of no interest and to avoid making the system store monitoring data of no interest. However, by only storing data of interest the system becomes more vulnerable when storage devices do not work properly or break down. This vulnerability is particularly severe as the system is instructed to store the important monitoring data only. This type of problems is typically overcome by providing redundant storage systems.
Moreover, small surveillance or monitoring systems are more common today than for a couple of years ago as the cost of the hardware required has become less expensive. However, providing redundant storage in such small system may result in an extra cost that the system owner would like to avoid.